(6)Subject to sub-section (8), where the source of any receipt, deposit or investment in any tax year is claimed to be an amount added to income or deducted while computing loss, in the assessment of such person in any year prior to the tax year in which such receipt, deposit or investment appears (herein referred to as the preceding year) and no penalty was levied for such preceding year, then, the under-reported income shall include such amount as is sufficient to cover such receipt, deposit or investment.